DEET, a popular synthetic insect repellant.
DEET- Numerous repellent products include the active component DEET (N,N-diethyl-meta-toluamide). It is frequently used to ward off biting insects like ticks and mosquitoes. DEET can be applied to kids of any age, according to the FDA. Since results from studies conducted for product registration reveal no difference in effects between young animals and older animals, there is no restriction on the proportion of DEET in the product for use on children.
Insect Repellant- Products that discourage insects are known as insect repellents. These might be skin care products or items like candles or lanterns with heating mechanisms that release repellents.
To know more about the DEET, click on the below link,
brainly.com/question/9866118
#SPJ4
Deserts has a very dry and hot climate, this may increase the water loss of plants through the leaves. Therefore, to prevent large amount of water loss in cactus, their leaves are modified to spines to reduce the surface area. In addition, the thick photosynthetic stems can help absorb and store more water, which is the necessary element for living things.
Answer:
They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste,and the deep biosphere of the earth's crust. Bacteria also live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, and only about 27 percent of the bacterial phyla have species that can be grown in the laboratory.[5] The study of bacteria is known as bacteriology, a branch of microbiology.
viruse
A virus is a small infectious agent that replicates only inside the living cells of an organism. Viruses can infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea.
Best Answer:<span> </span><span>Before DNA, taxonomists use detailed comparative anatomy. As Louis Dollo, one of the greatest anatomists of all time, points out, evolution is irreversible.
Dollo's principle states:
"An organism is unable to return, even partially, to a previous stage already realized in the ranks of its ancestors.". According to this hypothesis a structure or organ that has been lost or discarded through the process of evolution will not reappear in exactly the same form in that line of organisms."
It means, that, no matter how closely two organisms may resemble one another, the products of convergent evolution can never resemble one another in every single detail. By examining them closely, evidence of separate ancestry will always reveal themselves. Dollo's principle has served taxonomy very well, although some taxonomists have unwisely abandoned comparative anatomy and rely instead on superficial similarity. They claim, for example, that bird hands must be the same as theropod hands because both of them have 3 fingers. Comparative anatomists, OTOH, would point out that bird hands have fingers 2-3-4 because of evidence from developmental biology and the 3 fingers of theropod hands are 1-2-3 based on fossil evidence, since primitive theropods such as Eoraptor and Herrerasaurus have vestigial fingers 4 and 5. Therefore, using Dollo's principle, we have determined that birds and theropods have evolved their 3 fingered hands independently of each other from a common ancestor with a 5 fingered hand.
Finally, to answer the question of whether snakes and worms share a recent common ancestor, we apply Dollo's principle by examining both animals in detail. Snakes have a vertebral column. They have jaws. Snakes have a lung and they have scales made of beta keratin. These structures are absent from worms. OTOH, these same structures are found only in vertebrates, but not in all vertebrates. The particular subgroup of vertebrates that have these uniquely shared characters are in fact the reptiles. Snakes therefore are reptiles, not worms. Further, since snakes and lizards share the unique character of paired hemipenes, snakes are in fact close relatives of lizards. Using Dollo's principle to study worms, we can also determine that not all worms share a recent common ancestor either. Some worms for example, have a coelom, but some have a pseudocoelom while others, such as the flat worms, have no coelom at all. Using comparative anatomy, it has been determined that annelid worms are in fact more closely related to arthropods and molluscs than they are to the round or nematode worms.
Dollo's principle has in fact resulted in a highly stable and useful classification. However, many contemporary taxonomists are either ignorant of it or disdains its use. The result is taxonomic chaos generated by those who fail to realize how powerful and useful Dollo's principle really is.</span>
